Check valves of the general type illustrated herein comprise a pair of generally semicircular valve discs or flaps which are mounted on a shaft or hinge pin for pivotal movement between open and closed positions relative to the flow passage through the valve body. In many instances heretofore, the hinge pin has been mounted in opposed openings in the valve body which extend through the valve body. Normally, removable plugs have been positioned in the openings after the assembly of the valve. At times, particularly after prolonged use, a possible leak path may occur through the openings about the plugs. Thus, it is highly desirable that the hinge pin be supported by the valve body without the use of any openings through the valve body thereby to eliminate any possible leakage through the valve body from openings for the support of the hinge pin. Also, certain specifications and standards require that no through openings be provided in the valve body.
Check valves have been provided heretofore in which the hinge pin is supported by means not extending through the valve body. For example, U.S. Pat. No. 4,896,695 dated Jan. 30, 1990 shows a check valve in which the hinge pin is supported by opposed lugs secured to the valve seat on the valve body. However, such an arrangement requires that the check valve discs must be contoured to receive the lugs since the valve discs do not seat about a complete circle on the valve seat.
U.S. Pat. No. 4,977,926 dated Dec. 18, 1990 likewise shows a check valve in which the hinge pin is supported on opposed clips which are mounted within recesses or slotted areas in the valve body which do not extend through the valve body. The clips include resilient fingers and the slotted areas are machined in the valve body bore to form the recesses for the clips.